Conventionally, a ferrule which is used as a connecting end of an optical fiber for transmitting and receiving optical signals in optical communication is usually obtained by forming ceramics consisting primarily of zirconia into a predetermined shape by injection molding or the like, and then baking thereof. The ferrule is provided a through-hole for inserting an optical fiber and is used as a ferrule assembly to hold and fix the optical fiber in the through-hole. The ferrule assembly is widely used in optical connectors that are used to connect optical fibers together and to establish a communication path, or in a semiconductor laser module that is constituted by a semiconductor laser, the optical fiber and the like.
The optical connector is widely used to transmit the optical signals emitted from the semiconductor module or the like to another optical component through the optical fiber, or used as relay members connected between the optical fibers to transmit the optical signals to the optical component placed at a far distant location. The optical connector in this type is a preferred connection configuration that opposite ferrule ends each other are accurately and closely contacted therebetween and axis lines of the ferrules (specifically, axis lines of cores of the ferrules) are aligned each other to efficiently transmit light from one optical fiber to the other optical fiber. For the optical connectors, stability of assembling thereof at an on-site of connection and protection of connecting portion are required, and further, in order to minimize connection loss when the optical connectors are mutually connected, it is desirable to accurately align the cores of the optical fibers, and manufacturing error is required to be eliminated as much as possible. It is specified that the axis lines of the fiber cores must be aligned within a range of connection error of μm order when the optical fibers are connected together, so that not only a high degree of accuracy is required for shapes and dimensions of components constituting the optical connector which becomes the connection ends, but also the utmost attention must be paid to assembling the optical connector.
A communication path is established by inserting the optical connector described above into an opening of a jack socket disposed on a panel such as a wall. When the optical connector is inserted into the opening of the jack socket, a latch formed integrally with a housing of the optical connector is interlocked in the opening of the jack socket and held in order not to fall easily. In addition, there are many situations to be used the optical connectors which are oppositely connected in an adapter housing to extend the optical fiber.
An example of the optical connector having the above-described configuration is disclosed, for example, in the Japanese Patent No. 3996335 of Patent Document 1. In a conventional optical connector 50 shown in FIGS. 8 and 9, a housing 51 which has a rectangular outer shape and is cylindrically formed a main body, and a cavity 52 is formed in the housing. A latch 53 is integrally provided on the housing 51, and the housing 51 is held by interlocking, engaging the latch in the opening of the jack socket fitted to a panel or the like. A ferrule assembly 54 which has a ferrule 55 to establish a communication path is accommodated in the cavity 52. A compression coil spring 56 is fitted around the ferrule assembly 54, and the ferrule assembly is retained in the cavity so as to be elastically advanced or retracted by an elastic resilient force of the compression coil spring 56, and is resiliently connected to another opposite ferrule (not shown), and a communication path is established. In the drawings, numeral 61 denotes a dust cap for protecting the ferrule from dust, dirt, and stains.
As specifically shown in FIG. 9, the ferrule assembly 54 has the ferrule 55 and a holder 57 which holds it, and the holder 57 has a guide sleeve 57a to guide the compression coil spring 56, and a flange 57b formed to a hexagonal column shape to be urged by the compression coil spring 56. A truncated cone shaped guide portion 57c which is continued to the flange 57b is formed in the front portion where the ferrule is fitted.
And, the ferrule assembly 54 is accommodated in the housing 51 in a state that the guide sleeve 57a is supported by an insertion 58, and an optical connection end of the ferrule 55 is projected toward an opening 51b of one end of the housing 51. At this time, the holder 57 of the ferrule assembly 54 is fitted into a recess 51a and a recess 51d which have shapes which have corresponding to the holder 57, and as shown in FIG. 8, an opening 51c of the other end is closed by a sealing member so that the projection position of the ferrule 55 is established. By the sealing by the sealing member 60, therefore, a front end of a trigger lever 60a projected from the sealing member 60 is positioned above the latch 53 of the housing 51. By pressing the trigger lever 60a downward, the latch 53 opposite thereto descends resistively against an elastic force, so that an interlock of the optical connector 50 inserted into an opening of a jack socket or the like is released and is able to be pulled out therefrom.
Patent Document 1: Japanese Patent No. 3996335